T5X®Heavy Duty Diesel Engine Oil

Heavy-Duty Monograde Diesel Engine Oil

Phillips 66®T5X Heavy Duty Diesel Engine Oil is a high-quality diesel engine oil designed for use in a wide variety of applications, including off-highway diesel equipment, farm machinery, marine engines, 2-stroke cycle diesel engines (SAE 40 only) and mixed commercial fleets. It also may be used in some heavy-duty manual transmissions in trucks and buses.

Features & Benefits

• Excellent soot control for protection against abrasive wear and soot-induced oil thickening

• Protects against sludge and varnish formation

• Protects against scuffing and wear

• Protects against rust and bearing corrosion

• Good resistance to foaming and aeration

• Low-ash content to minimize ash deposits and help keep intake ports clean (SAE 40)


• 2-stroke cycle diesel engines in bus fleets and marine fleets (SAE 40)

• Off-highway trucks, heavy equipment and farm equipment

• Light trucks and farm equipment with gasoline engines (SAE 30, SAE 50)

• Heavy-duty manual transmissions in trucks and buses where the OEM specifies engine oil

Technical Details

Licenses & Approvals

T5X Heavy Duty meets or exceeds the requirements of:

• API Service CF-2(1), CF(1) (SAE 40)

• API Service CF(1), SL (SAE 30, SAE 50)

• Detroit Diesel 2-stroke cycle engines, Oil Type 1 (1.0% max. sulfated ash (SAE 40))

Additional Details
SAE Grade30
Specific Gravity @ 60°F0.883
Density, lbs/gal @ 60°F7.35
Color, ASTM D15004
Flash Point (COC), °C (°F)230 (446)
Pour Point, °C (°F)-33 (-27)
Viscosity, Kinematic
cSt @ 40°C92
cSt @ 100°C11.3
Viscosity Index110
High-Temp/High-Shear Viscosity, cP @ 150°C3.4
Sulfated Ash, ASTM D874, wt %1.39
Total Base Number (TBN), ASTM D289610.5
Zinc, wt %0.119